我将在下面发布我的代码，然后在下面指出我的问题。
#include <stdio.h>
#include <string.h>
//initializing the array
int arrayElements(array)
{
for (int i = 0; i <= strlen(array); i++)
{
printf("Enter array element:\n");
scanf("%d", &array[i]);
}
printf("Elements: ");
for (int i = 0; i <= strlen(array); i++)
{
printf("%d, ", array[i]);
}
}
//sorting the array
int arraySort(int array)
{
char sortType;
printf("Sort in Ascending or Descending order? [A\D]\n");
scanf("%c", &sortType);
while ((sortType != "A") || (sortType != "D"))
{
printf("Invalid selection.\n");
printf("Sort in Ascending or Descending order? [A\D]\n");
scanf("%c", &sortType);
}
if (sortType == "A")
{
ascending(array);
}
else
{
descending(array);
}
}
//searching the array
int arrayFind(int * array)
{
int searchElement;
int *d;
int i;
int **string;
printf("What element do you wish to search for?");
scanf("%d", &searchElement);
d = strint (array, searchElement);
if (d != NULL)
{
for (i = 0; i <= strlen(array); i++)
{
if (string[i] == searchElement)
{
printf("Element found at array[%d]\n", i);
}
}
}
else
{
printf("Element '%d' not found\n", searchElement);
}
}
//printing the array
int arrayPrint(array)
{
printf("%d", array);
}
//printing array in reverse order
int arrayRevPrint(array)
{
int **size;
for (size = strlen(array); size >= 0 ; size--)
{
printf("%d",array[size]);
}
}
int main()
{
int userSelection;
int size;
int elements;
int searchElement;
while (userSelection != 7)
{
printf("Please enter your selection\n>");
printf("1 - Enter the size of the array:\n");
printf("2 - Enter the array elements:\n");
printf("3 - Sort the array\n");
printf("4 - Find a number within the array\n");
printf("5 - Print the array\n");
printf("6 - Reverse print the array\n");
printf("7 - Quit\n");
scanf("%d", &userSelection);
switch (userSelection)
{
case 1 :
size=0;
while ((size > 20) || (size < 1))
{
printf("What is the size of your array? (1 - 20)\n");
scanf("%d", &size);
if ((size > 20) || (size < 1))
{
printf("Invalid selection.\n");
}
int *array[size];
printf("\nSize of array: array[%d]\nReturning...", size);
break;
}
case 2 :
if (size == 0)
{
printf("You should first set the size of the array.\n");
}
else
{
arrayElements(array);
}
case 3 :
if (elements == NULL)
{
printf("You should first intitialize the array.\n");
}
else
{
arraySort(array);
}
case 4 :
if (elements == NULL)
{
printf("You should first intitialize the array.\n");
}
else
{
int arrayFind(array);
}
case 5 :
if (elements == NULL)
{
printf("You should first intitialize the array.\n");
}
else
{
arrayPrint(array);
}
case 6 :
if (elements == NULL)
{
printf("You should first intitialize the array.\n");
}
else
{
arrayRevPrint(array);
}
case 7 :
printf("Exiting...");
return 0;
default :
printf("That's not a valid choice\n");
}
}
}
现在，我遇到了两个主要问题。我会发布每个中的一个，因为我得到了一堆不同的行。
第一个是，
error at line 137: switch jumps into scope of identifier with variably modified type.
第二个是
error at line 10: subscripted value is neither an array nor pointer nor vector
另外，我试图理解为什么我必须在某些函数中重新声明int size;，如果我已经在main函数中声明了它。
非常感谢任何建议。谢谢 PS，这是C分配介绍，我知道这很糟糕。但如果我能让它发挥作用，我可以忽略这些警告。
答案 0 :(得分：0)
您的代码可以编译许多错误。在使用指针方面，代码中似乎存在许多基本错误。我将尝试在您的代码中指出其中的一些，您可以先从纠正它们开始。我假设您正在寻找使用'size'元素初始化数组。
int *array[size];
在switch：case 1中，上面的声明意味着你正在初始化一个'size'数组的整数指针。您可能希望将其初始化为int *array = (int *)malloc(sizeof(int) * size);
接下来，对于所有功能，您需要将传递给函数的参数作为整数指针。我将纠正你的arrayelement（）函数，你也可以对其他函数进行相同的更改。同样在for循环中，您正在计算错误的数组长度。这是arrayElement（）函数的更正版本：
int arrayElements(int *array)
{
for (int i = 0; i < ((strlen(array))/sizeof(int)); i++)
{
printf("Enter array element:\n");
scanf("%d", &array[i]);
}
printf("Elements: ");
for (int i = 0; i < ((strlen(array))/sizeof(int)); i++)
{
printf("%d, ", array[i]);
}
}
同样将传递给所有函数的参数更改为funcName(int *array)。并且还将数组的大小计算为：((strlen(array))/sizeof(int))。
'size'是main（）函数的局部变量。如果您不想在所有函数中初始化它，您可以将其作为参数传递给所有函数，或者您可以将'size'作为全局变量。这些是代码中一些非常明显的错误。
答案 1 :(得分：0)
逻辑和语法都有很多错误。我删除了所有的语法错误和几乎所有的逻辑错误。我已经评论了代码中的错误以及我如何编辑它。请看一下代码。
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
// Its a good practice to mention your definitions of functions on the top.
void arrayElements(int arr[], int size);
void arraySort(int arr[], int size);
void arrayPrint(int arr[], int size);
void arrayRevPrint(int arr[], int size);
void arrayFind(int arr[], int size);
//initializing the array
//Function not returning anything use void instead of int
void arrayElements(int arr[], int size) // Modified signature
{
int i;
for (i = 0; i <= size; i++)
{
printf("Enter array element:\n");
scanf("%d", &arr[i]);
}
//Since you just want to print the array you can directly call arrayPrint() function.
// printf("Elements: ");
// for (i = 0; i <= size; i++)
// {
// printf("%d, ", arr[i]);
// }
arrayPrint(arr,size);
}
//sorting the array
//Function not returning anything use void instead of int
void arraySort(int arr[], int size) // Modified signature
{
char sortType;
printf("Sort in Ascending or Descending order? [A\\D]\n"); // to use an escape charachter
// use \ before them.
//To know more about escape characters please surf the internet.
scanf("%c", &sortType);
// Character literal are always bound between single quotes.
while ((sortType != 'A') || (sortType != 'D'))
{
printf("Invalid selection.\n");
printf("Sort in Ascending or Descending order? [A\\D]\n");
scanf("%c", &sortType);
}
// Where are the functions ascending and descending declared??
// Define the functions.
if (sortType == 'A')
{
//ascending(arr);
}
else
{
//descending(arr);
}
}
//searching the array
//Function not returning anything use void instead of int
void arrayFind(int arr[], int size)// Modified signature
{
int searchElement;
//int *d; No need of this
bool found = false; // A flag which we will turn true if element found.
int i;
//int **string; No need of this
printf("What element do you wish to search for?");
scanf("%d", &searchElement);
//d = strint (array, searchElement); No need of this
//if (d != NULL)
//{
for (i = 0; i <= size; i++)
{
if (arr[i] == searchElement)
{
printf("Element found at array[%d]\n", i);
found = true;
break; // Element has been found so for coming out of the loop
}
}
if (found == false)
{
printf("Element %d not found \n", searchElement);
}
// No need of the extra code below
//}
// else
// {
// printf("Element '%d' not found\n", searchElement);
// }
}
//printing the array
//Function not returning anything use void instead of int
void arrayPrint(int arr[], int size) // Modified signature
{
// You can not print array like this in c.
//printf("%d", array);
// To print an array in c you have to loop through it.
int i;
for(i=0; i<size; i++){
printf("%d ", arr[i]);
}
}
//printing array in reverse order
//Function not returning anything use void instead of int
void arrayRevPrint(int arr[], int size) // Modified signature
{
int i;
for (i=size-1; i >= 0 ; i--)
{
printf("%d ",arr[i]);
}
}
int main()
{
int userSelection;
int size;
bool elements = false; // I guess you wanted it to use as a flag for whether there
// there are elements in the array or not.
// In order to do that better use a boolean and set its default value
// to false.
int searchElement;
int *arr; // Your Dynamic array
while (userSelection != 7)
{
printf("Please enter your selection\n>");
printf("1 - Enter the size of the array:\n");
printf("2 - Enter the array elements:\n");
printf("3 - Sort the array\n");
printf("4 - Find a number within the array\n");
printf("5 - Print the array\n");
printf("6 - Reverse print the array\n");
printf("7 - Quit\n");
scanf("%d", &userSelection);
switch (userSelection)
{
case 1 :
size=0;
while ((size > 20) || (size < 1))
{
printf("What is the size of your array? (1 - 20)\n");
scanf("%d", &size);
if ((size > 20) || (size < 1))
{
printf("Invalid selection.\n");
continue; // to skip the next statements and continue the loop
}
arr = (int*)malloc(sizeof(int)*size); // Allocating given size to the dynamic array
printf("\nSize of array: array[%d]\nReturning...", size);
}
break; // Use break between two cases of a switch if two are not meant
// execute in a sequence.
case 2 :
if (size == 0)
{
printf("You should first set the size of the array.\n");
}
else
{
arrayElements(arr, size); // Always send the size as when you pass array
// it goes to the function as a reference to the array
// Hence, you can't calculate the size in the called function.
elements = true; // We have populated the array now so have to change the flag.
}
break;
case 3 :
if (elements == false)
{
printf("You should first intitialize the array.\n");
}
else
{
arraySort(arr, size); // Always send the size as when you pass array
// it goes to the function as a reference to the array
// Hence, you can't calculate the size in the called function.
}
break;
case 4 :
if (elements == false)
{
printf("You should first intitialize the array.\n");
}
else
{
arrayFind(arr, size);// Always send the size as when you pass array
// it goes to the function as a reference to the array
// Hence, you can't calculate the size in the called function.
}
break;
case 5 :
if (elements == false)
{
printf("You should first intitialize the array.\n");
}
else
{
arrayPrint(arr, size);// Always send the size as when you pass array
// it goes to the function as a reference to the array
// Hence, you can't calculate the size in the called function.
}
break;
case 6 :
if (elements == false)
{
printf("You should first intitialize the array.\n");
}
else
{
arrayRevPrint(arr, size);// Always send the size as when you pass array
// it goes to the function as a reference to the array
// Hence, you can't calculate the size in the called function.
}
break;
case 7 :
printf("Exiting...");
return 0;
default :
printf("That's not a valid choice\n");
}
}
}
注意：你还没有定义ascending（）和descending（）函数，这就是我对它们进行了评论的原因。请为这些功能编写必要的代码。